Second generation acrylic adhesives (SGA's) which are acrylic-based adhesives containing polymeric tougheners are known in the art. U.S. Pat. Nos. 3,890,407; 4,106,971; and 4,112,013 disclose adhesive systems composed of solutions of chlorosulfonated polyethylene or mixtures of sulfonyl chlorides and chlorinated polymers in polymerizable vinyl (preferably acrylic) monomers which cure to high bond strengths. U.S. Pat. No. 3,994,764 discloses an SGA system derived from a solution of a thermoplastic, nonreactive polyester- or polyether-based polyurethane resin in an addition polymerizable combination of an acrylic or methacrylic monomer and a copolymerizable monomer containing at least one free carboxylic acid group. U.S. Pat. No. 4,126,504 discloses the use of a thermoplastic nonreactive elastomer (typically based on at least one of butadiene, neoprene, and their derivatives) dissolved in an addition polymerizable combination of an acrylic or methacrylic monomer and a copolymerizable monomer containing at least one free carboxylic group to give a second generation acrylic adhesive. U.S. Pat. No. 4,138,449 discloses an SGA comprising a butadiene/acrylonitrile rubber having an acrylate end group dissolved in an acrylic, methacrylic, or dimethacrylic ester monomer.
European Patent Application No. 87,304 discloses non-aqueous compositions useful as, or in, low odor adhesives comprised of a sequential polymer (frequently designated as a core/shell polymer), of at least 25% by weight of an elastomeric stage and 5% by weight of an outermost rigid stage, dispersed (not dissolved) in an acrylic or methacrylic ester monomer, including blends of such monomers. These monomers (e.g. acryloyloxypropionic acid) have a flash point greater than 95.degree. C., and form a polymer whose glass transition temperature (T.sub.g) falls within the range of 0.degree. to 100.degree. C.
The cited art suffers from one or more of the following deficiencies: first, the common use of lower molecular weight monomers (i.e., lower esters of acrylic and methacrylic acid, e.g. methyl methacrylate) results in a noxious odor problem, often in conjunction with undesirable flammability and toxicity characteristics; second, the use of higher molecular weight monomers to avoid odor, flammability, and toxicity problems can have other effects. For example, the higher molecular weight monomer may become a solid, leading to formulation difficulties. Also, the T.sub.g of a polymer usually decreases as the molecular weight of the monomer increases, resulting in a loss of performance characteristics in the adhesives. In addition, the higher molecular weight monomers may not be suitable for dissolving the polymeric tougheners.
U.S. Pat. Nos. 4,322,504; 4,308,014; 4,393,237; and 3,658,624 disclose the use of substituted acrylamides and methacrylamides, with and without other functional groups present in the substituents, for use in resin binders, medical and dental bonding agents, and untoughened adhesives.
U.S. Pat. No. 2,658,056 discloses a method of making cyclic amines by the reaction of acrylyl chloride and methacrylyl chloride.
U.S. Pat. No. 4,718,899 discloses water-insolubilized products of N-alkyl- or N-alkylene-substituted (metha)acrylamides used for absorbing and releasing urine.
U.S. Pat. No. 3,876,594 discloses copolymers containing N-acryloyl-morpholine, -piperidine, or -pyrolidine used for filling postoperative cavities.
U.S. Pat. No. 4,062,831 discloses N-acrylomorpholine and N-acryloyl piperidine as possible components in the preparation of polymers for use as membrane and as packing for chromatography columns.
Of the above cited art, only U.S. Pat. Nos. 3,994,764 and 4,126,504 broadly disclose N-substituted acrylamides as potential vinyl monomers, although none are exemplified by the patentees. These two patents, in addition, use tougheners which are soluble and non-reactive with respect to the acrylic monomers.